From 6ec200adcff2dd973b64485c238405a377bb7b91 Mon Sep 17 00:00:00 2001
From: Johannes Marbach <johannesm@element.io>
Date: Fri, 25 Apr 2025 14:35:18 +0200
Subject: [PATCH] Stabilise MSC3765 (#4767)

* Stabilise MSC3765

Signed-off-by: Johannes Marbach <n0-0ne+github@mailbox.org>

* Remove unstable content and hardcode property name

---------

Signed-off-by: Johannes Marbach <n0-0ne+github@mailbox.org>
---
 spec/unit/content-helpers.spec.ts | 8 ++++----
 src/@types/topic.ts               | 9 +++------
 src/content-helpers.ts            | 8 +++++---
 3 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/spec/unit/content-helpers.spec.ts b/spec/unit/content-helpers.spec.ts
index 79c2f7726..623288d7b 100644
--- a/spec/unit/content-helpers.spec.ts
+++ b/spec/unit/content-helpers.spec.ts
@@ -196,14 +196,14 @@ describe("Topic content helpers", () => {
             expect(makeTopicContent("pizza", "<b>pizza</b>")).toEqual({
                 topic: "pizza",
                 [M_TOPIC.name]: [
-                    {
-                        body: "pizza",
-                        mimetype: "text/plain",
-                    },
                     {
                         body: "<b>pizza</b>",
                         mimetype: "text/html",
                     },
+                    {
+                        body: "pizza",
+                        mimetype: "text/plain",
+                    },
                 ],
             });
         });
diff --git a/src/@types/topic.ts b/src/@types/topic.ts
index fd6e81a41..b11bf3bc4 100644
--- a/src/@types/topic.ts
+++ b/src/@types/topic.ts
@@ -13,7 +13,7 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */
-import { UnstableValue } from "../NamespacedValue.ts";
+import { NamespacedValue } from "../NamespacedValue.ts";
 import { type IMessageRendering } from "./extensible_events.ts";
 
 /**
@@ -42,20 +42,17 @@ import { type IMessageRendering } from "./extensible_events.ts";
 /**
  * The event type for an m.topic event (in content)
  */
-export const M_TOPIC = new UnstableValue("m.topic", "org.matrix.msc3765.topic");
+export const M_TOPIC = new NamespacedValue("m.topic");
 
 /**
  * The event content for an m.topic event (in content)
  */
 export type MTopicContent = IMessageRendering[];
 
-type MTopicStable = { [M_TOPIC.altName]: MTopicContent };
-type MTopicUnstable = { [M_TOPIC.name]: MTopicContent };
-
 /**
  * The event definition for an m.topic event (in content)
  */
-export type MTopicEvent = (MTopicStable & MTopicUnstable) | MTopicStable | MTopicUnstable;
+export type MTopicEvent = { "m.topic": MTopicContent };
 
 /**
  * The event content for an m.room.topic event
diff --git a/src/content-helpers.ts b/src/content-helpers.ts
index 16b3731e1..6ebc1f659 100644
--- a/src/content-helpers.ts
+++ b/src/content-helpers.ts
@@ -189,12 +189,14 @@ export type MakeTopicContent = (topic: string | null | undefined, htmlTopic?: st
 
 export const makeTopicContent: MakeTopicContent = (topic, htmlTopic) => {
     const renderings = [];
-    if (isProvided(topic)) {
-        renderings.push({ body: topic, mimetype: "text/plain" });
-    }
+    // Put HTML first because clients will render the first type in
+    // the array that they understand
     if (isProvided(htmlTopic)) {
         renderings.push({ body: htmlTopic, mimetype: "text/html" });
     }
+    if (isProvided(topic)) {
+        renderings.push({ body: topic, mimetype: "text/plain" });
+    }
     return { topic, [M_TOPIC.name]: renderings };
 };